In this work Strontium doped copper oxide nanoparticles were prepared by sol gel method. Different samples were prepared by changing the concentration of Strontium . Prepared samples were studied using X ray diffraction and analysis shows that particles size increases with increase in strontium concentration from 34.7nm to 89.9nm. UV-VIS spectroscopy shows that band gap decrease with increase in strontium concentration from 5.39 eV to 5.10 eV.